Commonly, ICs are mounted on a leadframe and wires are provided between the electrical contacts (pins) of the IC and corresponding electrical contacts on the leadframe. To protect the wires, the leadframes and ICs are encapsulated in plastics material which surrounds and supports the wires. The result of this process is the production of an IC package.
It is common for a manufacturer to provide a family of ICs in which different members of the family have different lead counts. For example, the small outline integrated circuit (SOIC) family has members having 8, 14, 16, 20, 24 and 28 pins. When it is desired to encapsulate these ICs in plastic material to form an IC package, a moulding system is employed which is tailored to the number of leads present on the corresponding IC.